Method of shaping sheet pyroxlin and the like



Feb. 16 1926. 1,573,356

E. R. PERSON METHOD OF SHAPING SHEET PYROXYLIN AND THE LIKE OriginalFiled March 15, 1922 KWQKWW Patented Feb. 16, 1926.

T AT E S PATET @FFlCE.

EARL R. PERSON, F LEOMINSTER, MASSACHUSETTS, ASSIGNOR TO THE VISCOLOIDCOMPANY, A CORPORATION OF MASSACHUSETTS.

METHOD OF SHAPING SHEET PYROXLIN AND THE LIKE.

Original application filed March 15, 1922, Serial No. 543,938. Dividedand this application filed November 19, 1923. Serial No. 675,475.

To all whom it may concern Be it known that I, EARL R. .PnnsoN, acitizen of the United'States, residing at Leominster, in the county ofVorcester and State of Massachusetts, have invented a new and usefulMethod of Shaping Sheet Pyroxylin and the like, of which the followingis a specification.

- This is a division of my Patent No.

1,492,179 granted April 29, 1924 on an application filed March 15, 1922,Serial No. 543,938. a

This invention relates to the manufacture of barrettes, pins and otherdevices of pyroxylin in sheet form. Heretofore the sheet pyroxylin' hasbeen stamped out to the desired shape by cutting dies and then the edgessmoothed and the necessary curvature put in it by a separate operation.This necessitated the production of an article having substantiallyuniform surfaces on.

both sides because there was no convenient way of changing the thicknessof the sheet material. Furthermore, in orderto get an 7 article of anyspecific thickness :1. blank of the same thickness had to be used.

The principal object of this invention is to provide a method ofmanufacturing such an article out of a blank thinner than the completedarticle will be and provide for varying the thickness of the completedarticle to any reasonable degree so that a product can be secured whichwill have convex surfaces on its front face, thus makin it much moreattractive and salable; an to provide for securing these results bysimple die punching and pressing operations and without complicating theprocedure.

Further objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawings, in which Fig. 1 isa plan and longitudinal section of a blank cut out in the usual way andconstituting the material on which the device operates;

Fig. 2 is a front elevation of a com lete set of dies and punches madein accor ance with this invention, shown separated and partly insection;

Fig. 3 is a perspective view of the dapper e Fig. 4 is an end view ofthe devices shown in Fig. 2, but illustrating them in the positionassumed when in operation; and

Fig. 5 is a view similar to Fig. 1, showing the finished product.

As'has been the case heretofore, a blank of sheet pyroxylin or the likeof whatever gauge is desired, say for example, 75/1000 is cut by anordinary cutter to produce the blank shown in Fig. 1. This has the sameoutline and general design as the finished article to be produced. Theseblanks are cut from hot material, leaving a comparatively smooth edgebut this has to be smoothed all over further by placing the blanks in atumbling outfit or rumble. After being tumbled for some time the blanksare put in the press, heated and operated upon by the (lapping-up toolor die shown in Figs. 2, 3 and 4. This die changes the material to athickness of perhaps 90/1000 of an inch, bends it into finished shapeand rounds off the edges of the article. After this process is completedthe article is then put into another rumble and tumbled, polished andfinished as is the usual custom.

The first step of the above mentioned process can produce a blank A suchas shown in Fig. 1. This is flat and is usually provided with one or,ITIOIG perforations as a. 'This blank is of the same thickness as thesheet of pyroxylin from which it is cut. The set of dies into which itis placed comprises abase 10,-a plate 11 resting thereon and a secondplate 12. The plates 11 and 12 are perforated for dowels 13 whichconstitute guides to keep these plates in proper registration with eachother. On the base 10 there are two stationary cores 14 in the presentinstance, corresponding in shape and size with the perforations a. Fixedon the plate 11 is the dapping die proper 15. This clapping die is aprojection having the external shape of the blank A and provided withperforations 16 of the same shape as the cores 14. The upper surface isof a general concave form to give the eneral convex shape to the articlewhich is esired. It has a molding surface 17 for receiving the bottomsurface of the blank A and shaping it and this surface is of concaveform throughout such part of it as is intended for producing a. localconvex sha e on the article to be produced.' The dept of concavity ofthis surface 17 is greater than the thickness of theblank A. The heightof the die 15 is just equal to the width of the plate 12 atcorresponding locations.

The plate 12 has an upper concave surface at 20, as stated,corresponding with the general concavity of the surface 17 from one endto the other. In other words, when the plate 12 is located in moldingposition, as shown in Fig. 4, the extreme upper surfaces of the plate 12and the dapping die 15 correspond 'to'form a portion of acylindricalsurface. The plate 12, of course, has a perforation 21 therethrough forreceiving the dap'ping die 15 and 1t exactly fits it.

Above all these parts so far described is a plunger plate 25 having aplunger 26 thereon. This plate has dowels 27 for guiding it inperforations in the plate below and the plunger 26 has perforations28,or at least depressions, for receiving the cores 14. This plunger is ofthe exact shape of the blank A- externally and has a convex bottomsurface corresponding with the concave surface 20. Its lower edge whichcon stitutes its molding surface is smooth and fiat except that it isconvex in the manner specified.

The process of-production is as follows:

When the plate 25 islifted the operator places the flat blank A in theconcavity within the center of the top surface of the plate 12 andcompresses it down into curved position against the top of the die 15.It will be held there by the fact that its ends engage theedge surfacesof the plate 12 as the die 15 does not come quite to the top of it atthe ends. It will be remembered that it is heated. N ow, the plunger 26is forced down on the material and held down to shape the heated blankto the form of the -mold. That is, it gives it the form of the completedarticle B, shown in Fig. 5. This article has a general curved shape fromone end to the other or, of course, it may, have a wavy or any othershape, but its back, that is, its upper surface, is smooth and continueously concave. Its front surface, the one that is to be exposed when thearticle is worn, instead of is rounded at its edges and each section ofit is convex on the front, as shown in the sectional view in Fi' 5. Thetotal thickness of the complete article 18 is considerably greater thanthat of the blank A. The

' perforations b are not modified except that.

eing flat like the blank A- their edges are slanting or convex insteadof straight as in the b1ank. The compression of the blank of celluloidbetween the parts of the mold sets the article in this form- Then theplunger is drawn up by the press, which is not shown, and the operatorpresses on a lever 30, the inner end of which is connected with theplate 11 which it moves up. This brings the molded article up above thecores so that-the operator can pick it out. It will be observed that theplunger is guided by the cores 14 as well as by the dowels and that theoperation is such as to produce an article which is much better finishedthan can be produced by an of the old methods known to me. Instea' ofleaving the article in the form of a substantially flat or at leastuniform blank, its front surface is actually molded and brought intosuch shape that it will pass for a hand carved article and the fact thatit is made from sheet material is entirely disguised. The finishing orpolishing operations are performed afterward as stated above.

' Although I have illustrated and described a certain procedure and onlyone shape of article, I am aware of the fact that the invention can becarried out with modifications in' the order of steps and that anarticle of practically any desired shape can be made without departingfrom the scope of the invention as expressed in the claim. Therefore, Ido not wish. to be limited to all the details herein shown and describedbut what I do claim is The method of molding sheet pyroxylin and thelike which consists in cutting out of a flat sheet a blank thinner thanthe article to be produced, perforating it at exactly the margins atwhich perforations are desired in the completed product so as to leavethe surfaces perpendicular to the flat surface of the .blank or sheetand so that the blank at all points will be reetangular in crosssection, smoothing the surfaces of the perforated blank and pressing itbetween two surfaces, one of which is concave and deeper than thethickness of the blank to force all the material originally cut out toform the blank into the die, whereby all the material of the perforatedblank is utilized and the product is materially thicker than theoriginal sheet.

In testimony whereof I have hereunto

